Two voltage shaver



Jan. 14, 1941. KNQPP 2,228,665

TWOIVOLTAGE SHAVER Filed July 15, 1940 Patented Jan. 14, 1941 UNITED STATES PATENT OFFICE 2,228,665 'rwo VOLTAGE SHAVER.

Application July 15, 1940, Serial No. 345,560

11 Claims.

the two field coils, either in parallel or in series.

Another object of the invention is to-provide a switch of simple and inexpensive construction which is particularly adapted for compact mounting in the restricted space to be found in the usual type of dry shaver, the housing of which'is rela tively small so that the shaver can be held in the palm of the hand during use.

Another object is to provide a switch which may be simply formed of four brushes and a rotor having bridging contacts, proper circuit connections being made between the brushes and the coils, circuit breaker and terminals of the shaver motor to eiiect a series circuit relation of the coils when the rotor is oscillated to one position and to effect a parallel circuit relation thereof when the rotor is oscillated to another position.

A further object is to provide a rotor which may be suitably journaled for oscillation in a two part housing for the shaver motor in such manner that when the two parts are separated from each other, the rotor can be removed for cleaning its contacts or forreplacement.

Still a further object is to provide a switch rotor with a means to eliminate the possibility oi rotating it while current is being supplied to the shaver.

Still another object is to provide a rotor which has a slot or the like in an exposed end thereof and which may receive the prong of a cord that supplies current to the shaver thereby insuring that the cord is disconnected from any source of current supply during the shifting of the rotor from one position to the other.

With these and other objects in view my invention consists in the construction, arrangement 45 and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawing. Although the invention is sus- 50 ceptible of a variety of embodiments,-it is unnecessary to fully describe and illustrate more than one in order to give a full understanding of the invention both from its structural and tunetional standpoints. Accordingly, I have illustrated a preferred and desirable embodiment of the invention in the accompanying drawing, in

which:

Figure 1 is a plan view of a dual voltage shaver embodying my invention, the upper half of the housing thereof being removed and the sockets for holding it in position shown in section.

I Figure 2 is a side elevation, partly in section, showing the right hand end of the shaver.

Figures 3 and 4 are diagrammatic viewsshowing respectively a switch rotor for adjusting two coils of the shaver in parallel as for 110 volt current and in series as for.220 volt current.

Figure 5 is an enlarged sectional view on the line5-5 of Figure 1 showing details of the rotor switch; and

Figure 6 is a similar sectional view 6-6 of Figure 1.

On the accompanying drawing I have used the reference character H to indicate generally a housing. The housing H is formed of a lower part l0 and an upper part I2. The parts l0 and [2 are secured together as by screws l3, which as shown in Figure 2 are counter-sunk in the part [0 and threaded into an imbedded sleeve M of the housing part I2. A head member [5 is associated with the housing H and is adapted to receive the usual stationary and movable elements of .a dry shaver cutter head indicated generally at H. I

A dry shaver of the character shown usually includes field laminae I 6 on which are wound one or more coils. Specifically I provide two coils in dicated at C and C. A tripole armature I1 magnetically coacts with the field laminae l6 so as to effect rotation of the armature through properly timed impulses of electric current supplied to the coil C and C .Such impulses are controlled by a circuit breaker consisting of a bracket I8 having a stationary contact l9 and an oscillatable bracket 20 having a movable con- 0 tact 2 I. The shaft of the armature I1 is indicated at 22. Mounted thereon is a three lobe cam 23 adapted to separate the contact 2| from the contact l9 against the action of a spring 24. The cam 23bears against an insulating strip 25 secured to the movable bracket 20. The bracket is pivoted as by a hub portion 26 oscillatably engaging a pin 21.

On the shaft of the armature I! is an eccentric '28. The eccentric coacts with a forked end of an operating arm 29 pivoted at 29a and adapted to f impart oscillations to the movable cutter member of the head H.

A resistor 3|! and a condenser '3l connected in series are shunted across the contacts I! and 2! 15 on the line to reduce arcing between them. The condenser 3| is located between the bracket and the coils C and C and the resistor is placed as shown in Figure l.

The rotor R has reduced cylindrical ends 32 which are rotatable in half bearings indicated as notches 33 and 34 (see Figure 2) formed in the lower and upper parts III and [2 respectively of the housing H. The rotor R is preferably formed of insulating material and is seated against a base block 35 which in turn is secured to a cross member 36 of the frame of the motor. Screws 3! are provided as shown in Figure 5 for securing the block 35 in position and the seat in the block is indicated at 38.

The block 35 has imbedded therein a pair of brushes I and 2 which are shaped as shown in Figure 6. The portions of the brushes l and 2 which contact with the rotor R are on the left side of the rotor as shown in the drawing. Other brushes 3 and 4 are also imbedded in the block 35 and are on the opposite side of the rotor. The rotor has bridging contacts B 3 and B In one position of the rotor (for 110 volt operation) the bridging contact 1B connects the brush l with the brush 3 and the bridging contact B connects the brush 2 with the .brush 4 as shown in Figure 3. I In the other position of the rotor,

the bridging contact B bridges thebrushes 3 and l as shown in Figure 4 for 220 volt operation.

The rotor R is limited to a quarter turn of movement by pair of stop pins 39, the pins 39 are adapted to engage the housing part I! in one position as shown by full lines in Figure 5 and the block 35 in the other position of the rotor as shown by dotted lines. One end of the rotor R is slotted as indicated at 40 to receive one of the prongs ll of a cord plug 42. The cord 0! the plug is indicated at 43 and the socketed plug thereof is indicated at H. The socketed plugof course is for connection to the terminal prongs T and T while the prong plug 42 is for normal connection to a service outlet. It is desirable when operating my 'switch however that the cord 43 be disconnected from the outlet and accordingly I designed the rotor R so that it is adapted to be operated by inserting one of the prongs H in the slot lll which necessitates removing the prongs from connection with the service outlet. In this way undesirable sparking of the rotorR or any possibility of any undesirable short circuits while adjusting from one position to the other are eliminated.

Circuit connections are made between the terminals, the coils, the circuit breaker and the switch of my shaver in the following manner. A wire t connects the terminal T with the brush i. A wire'a connects the brush l with one end of the coil C The other end of theicoil C is connected by a wire a-' to the brush 4. The other terminal 'I is connected by a wire t to the contact breaker which in turn is connected by a =wire t to a wire D The wire b connects one end of the coil '(3 to the brush 2 while the other end of the coil 0'' is connected by a wire I; to the brush 3.

Practical operation a terminal bracket 45, the spring 24, the bracket III, the contacts II and I! of the circuit breaker, the bracket I8 and the wire t to the terminal '1'. The dividing of the current between the brush l and the wire t causes it to fiow in parallel paths through the coils C and C. Also'the flow is such that it is in a certain direction through each of thecoils indicated by plus and minus signs, although of course the shaver can be operated on alternating current.

When the rotor R. is adjusted for 220 volt operation, the circuit may be traced as in Figure 4 from terminal T through elements t a, C a, 4,13 3, b", 0', W, F, 45, 24, 2|, II, II, II and t to T. The current now it will be noted passes through the coil C and C in series and it will be further noted that it passes in the same direction through these coils as it did in Figure 3. This is necessary so that the coils do not aid each other in one instance and buck each other in the other instance. The coils are wound of course so that in both instances they aid.,each other. The path connections to the brushes and the path arrangement of bridging contacts which I disclose efiect the proper circuit connections whether the coils are in parallel or in series.

By providing a switch in the form of a rotor and brushes as I have illustrated it is possible to make a very compact type of series-parallel switch so that it can be worked into the comparatively small space available in a dry shaver housing without any projections which would enlarge the housing and make it clumsy to fit in the user's hand. The switch is readily accessible for removal by merely separating the two parts of the housing H which coact with each other to journal the rotor when they are assembled together.

Some changes may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and it is my invention to cover bymy claims, any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a dual voltage shaver, a housing, a pair of current supply terminals thereon, a motor having a pair of electrical coils, an armature, and an armature operated circuit breaker, a switch for connecting said coils either in series or in parallel comprising a rotor, two pairs of brushes cooperating therewith, one pair of said brushes being on one side of said rotor and the other pair of said brushes being on the opposite side of said rotor, said rotor being movable to two positions and having on one side a single bridging contact for said first pair of brushes when in one of said positions and a pair of bridging contacts through ,the rotor for connecting the first pair of brushes with the other pair of brushes in the other position of the rotor, said brushes being connected; said first pair of brushes with one end of each of said coils, one

of the other pair of brushes with the other end of one of said coils and the other of the other pair of brushes with the other end oi? said other coil, said terminals being connected; one terminal with one of the first of said other pair of brushes and the other terminal through said circuit breaker with the other one of said other pair of brushes.

2. In a dual voltage shaver, a housing, a pair of current supply terminals thereon, a motor having a pair of electrical coils, a switch for conneclting said coils either in series or in parallel comprising a rotor, two pairs of brushes cooperating therewith, one pair of said brushes being on one side of said rotor andthe other pair of said brushes being on the opposite side of said rotor, said rotor being movable to two positions and having on one side a single bridging contact for said first pair of brushes when in one of said positions and a pair of bridging conltacts through the rotor for connecting the first pair of brushes with the other pair of brushes in the other position of the rotor, said brushes being connected;

said first pair of brushes with one end of each of said coils, one of the other pair of brushes with the other end 01 one of said coils and the other of said pair of brushes with the other end of said other coil, said terminals being connected; one terminal with one of the first of said other pair of brushes and the other terminal with the other one of said other pair of brushes.

3. In a dual voltage shaver, a pair of current supply terminals, a motor having a pair of electrical coils, a switch for connecting said coils either in series or in parallel comprising a rotor, two pairs of brushes cooperating therewith, one pair of said brushes being on one side of said rotor and the other pair of said brushes being on the opposite side of said rotor, said rotor being movable to two positions and having on one side a single bridging contact for said first pair of brushes when in one of said positions and a pair of bridging contacts through the rotor for connecting the first pair 01' brushes with the other pair of brushes in the other position of the rotor, and circuit connections between said coils, said brushes and said terminals to selectively effect series connection of said coils together through said single bridging contact or parallel connection of said coils with relation to each other through both of said pair of bridging contacts.

4. In a dual voltage shaver, a housing, a pair of current supply terminals thereon, a cord for supplying current to said terminals, a plug on the outer end of said cord, said plug having prongs for connection with a service outlet, a motor having a pair of electrical coils, an armature, and an armature operated circuit breaker, a switch for connecting said coils either in series or in parallel comprising a rotor, two pairs of brushes cooperating therewith, one pair of said brushes being on one side of said rotor and the other pair of said brushes being on the opposite side of said rotor, said rotor being movable to two positions and having on one side a single bridging contact for said first pair of brushes when in one of said positions and a pair of bridging contacts through the rotor for connecting the first pair of brushes with the other pair of brushes in the other position of the rotor, said brushes being connected; said first pair with one end of each of said coils, one of the other pair with the other end of-one of said coils and the other of said other pair-o1 brushes with the other end of said other.

coil, one of said terminals being connected with one of said other pair of said brushes and the other terminal being connected through said circuit breaker with the other one of said other pair of brushes, and said rotor having a slot with which one of said prongs of said cord plug may coact for imparting rotation to the rotor and thereby moving it to either of said positions.

5. A dual voltage shaver comprising a pair of current supply terminals, a cord for supplying current thereto, a plug on said cord and having prongs for connection with a service outlet, a motor having a pair oi, electrical coils, a switch for connecting said coils either in series or in parallel comprising a rotor, two pairs of brushes cooperating therewith, one pair of said brushes being on one side of said rotor and the other pair of said brushes being on the opposite side of said rotor, said rotor being movable to two positions and having on one side a single bridging contact for said first pair of brushes when in one of said positions and a pair of bridging contacts through the rotor for connecting the first pair of brushes with the other pair of brushes in the other position of the rotor, said brushes being connected, said first pair with one end of each of said coils, one of the other pair with the other end of one of said coils and the other of said other pair of brushes with the other end of said other coil, one of said terminals being connected with one of said other pair of said brushes and the other terminal being connected with the other one of said other pair of brushes, and said rotor having means of coaction with one of said prongs of said cord plug for imparting rotation to the rotor and thereby moving it to either of said positions.

6. A dual volt-age shaver comprising the combination of a housing, first and second current supply terminals carried thereby, a cord and a vpronged plug for supplying current to said terminals, a motor in said housing having first and second coils, an armature, and an armature operated circuit breaker; with a switch for connecting said coils in series or in parallel comprising a two position rotor having reduced cylindrical ends, said rotor being arranged transverse of said housing and having a slot to receive one of the prongs of said plug, said housing being formed in two parts, each of said parts having a socket,

said sockets, in conjunction with each other,

forming bearings for said cylindrical ends of said rotor, first, second, third and fourth brushes coacting with said rotor, said rotor having first, second and third bridging contacts, said first bridging contact being adapted to bridge said third and fourth brushes in one position of the rotor, said second and third bridging contacts being adapted to bridge said first brush with said third brush and said second brush with said fourth brush in the other position of said rotor, said brushes, contact breaker, coils and terminals being electrically connected and such connections comprising said first terminal with said first brush and with one end of said first coil, said second terminal with said contact breaker and, said contact breaker with said second brush and with one end of said second coil, the other end of said first coil being connected with said fourth brush and the other end of said second .coil being connected with said third brush.

7. A dual voltage shaver comprising the combination of a housing, first and second current supply terminals carried thereby, a cord and a pronged plug for supplying current to said terminals, a motor in said housing having first and second coils; with a switch for connecting said coils in series or in parallel comprising a two position rotor having means of coaction with one of said plug prongs for oscillating the rotor, first, second, third and fourth brushes coacting with said rotor, said rotor having first, second and third bridging contacts, said first bridging contact being adapted to bridge said third and fourth brushes in one position of the rotor, said second and third bridging contacts being adapted to bridge said first brush with said third brush and said second brush with said fourth brush in the other position of said rotor, said brushes, contact breaker, coils and terminals being electrically connected and such connections comprising said first terminal with said first brush and with one end 01' said first coil, said second terminal with said second brush and with one end of said second coil, the other endoi said first coil being connected with said fourth brush and the other end of said second coil being connected with said third brush.

8. A dual voltage shavervcomprising the combination of a housing, first and second current supply terminals carried thereby, a cord and a plug ior supplying current to said" terminals, a motor in said housing having first and second coils; with a switch for connecting said coilsin series or in parallel comprising a two position rotor, brushes coacting with said rotor, and circuit connections between said terminals, said brushes and said coilsto eiiect selectively said series or parallel connections oi.' said coils with relation to each other, said rotor having means of coaction with said plug whereby the plug may be used, when free of a service outlet, to manually eflect movement of said rotor to either of positions. a v I I 9. A dual voltage shaver comprising meow bination of first and second current supply terminals, a cord and a plug for supplying current to said terminals, a motor having first andsecond coils; with a switch for connecting said coils in series or in parallel comprising a two position element having first, second and third bridging contacts, first, second, third and fourth brushes coacting with said element, said first bridging contact being adapted to bridge said third and iourth brushes in one position of said. element, said second and third bridging contacts being adapted to bridge said first brush with said third brush and said second brush with said fourth brush in the other position oi said element, said brushes, contact breaker, coils and terminals being electrically connected and such connections comprising said first terminal with said first brush and with one end of saidfirst coil, said second terminal with said second brush and with one end of said second coil, the other end of said first coil being connected with said fourth brush and the other end of said second coil being connected with said third brush, said plug having means of coaction with said element to eiiect selective movement thereof to either of said positions.

10. In a dual voltage shaver, a housing having current supply terminals, a cord for supplying current thereto, said cord terminating in a pronged plug, a motor in said housing including a pair of electrical coils and means for connecting said coils either in series or in parallel circuit with relation to each other comprising a switch having a rotor arranged transversely in said housing, brushes coacting with said rotor and electrically connected with said coils and terminals, said rotor having a slotted portion-exposed through a wall of said housing and adapted to receive a prong oi. said cord plug for rotating said rotor, said housingbeing formed in two parts, each oi said parts having a hearing which cooperate with each other when the parts are assembled for oscillatably supporting said rotor.

11. In a dual voltage shaver, current 'supply terminals,'a cord for supplying current thereto, said cord terminating in a plug, a motor including a pair of electrical coils and means for connecting said coils either in series or in parallel circuit with relation to each other comprising a switch including brushes electrically connected with said coils and terminals, said switch having a portion adapted to coact with said cord plug for operating the switch thereby when the plug is disconnected from a service outlet.

RUDOLPH KNOPP. 

